1. Field of the Invention
The present invention relates to a bill counting apparatus used in, e.g., a banking organization and, more particularly, to a pack number detecting apparatus for detecting the number of packs of bills each of which is bound with a strip, and which are included in a bundle which is bound with bands to be conveyed.
2. Description of the Related Art
As an apparatus for counting bills, a pack count detecting apparatus for detecting a bundle of bills which is being conveyed to detect the number of packs included in the bundle is known. In this case, the "pack" is a predetermined number of bills (e.g., 100 bills) bound with a strip, and the "bundle" is, e.g., 10 packs bound with bands.
The pack number detecting apparatus employs a measuring method of detecting the number of packs included in a bundle in accordance with the weight of the bundle. More specifically, the weight of a bundle to be detected is measured, and it is checked whether or not the measured weight falls in a range between upper and lower limit values as comparison data of a weight prepared in units of types of bills. If the measured weight does not fall within the range, it is determined that the bundle does not include the predetermined number of packs.
However, when the number of packs is detected on the basis of a weight, the weight of bills may change under the influence of a foreign matter such as a tape adhered to a bill, a humidity upon measurement, and the like. For this reason, the measured weight of a bundle may erroneously fall outside a range between the upper and lower limit values of the weight, or may fall within the range although the weight does not actually reach a predetermined weight.
In this case, the upper and lower limit values of a weight must be set in accordance with the types of bills, resulting in a cumbersome setup operation. In order to measure a weight, a bundle which is being conveyed must be temporarily stopped, resulting in a limited processing speed.